| 摘要 |
<p>Saw-teeth are cut from webs of structural shapes which are to be reconnected in a conventional manner at the tips of the teeth so as to form light beams having a high moment of inertia. The method consists in cutting the web of the shape step-by-step between two tools, each comprising two zones, one of which is a shearing zone proper extending along the length equal to one pitch of the saw-teeth and in which each cutting edge of a tool is substantially parallel to the corresponding edge of the other tool and the other of which is a transition zone immediately preceeding the cutting zone and in which the corresponding cutting edges diverge.</p> |
